1. Technical Field
This invention generally relates to health products. More particularly, the invention relates to a monitoring device. Specifically, the invention relates to a device that aids in monitoring exposure to ultraviolet radiation (UVR) which includes a UVR sensitive material and a cover tape that are progressively removed to reveal the UVR sensitive material over a period of time.
2. Background Information
Over the past several decades, there has been a growing awareness of the dangers of overexposure of the skin to ultraviolet radiation from the sun. The climbing rates of skin cancers, awareness of problems with the ozone layer and media attention to these and other issues have made the general population more aware of the need to take preventive steps to protect their skin from potential damage. Some of these measures have included using specially manufactured UV blocking clothing, wearing of hats and sunglasses, and the application of sunblocks and sunscreens that contain protective chemicals.
All of these measures restrict the amount of UV radiation a person is exposed to. They do not, however, provide any real information about the actual quantity of UV radiation a person is receiving and whether or not that exposure level is safe.
There are several products available today that may be used to monitor a person's exposure to UVR. An example of such a device is found in U.S. Pat. No. 5,117,116 issued to Bannard et al, discloses a UV radiation detection device that is applied to the skin by way of an adhesive. The device comprises a housing having a UV sensitive material applied to an inner surface thereof. The top of the housing shields the UV sensitive material from direct exposure to UV radiation. When the UV sensitive material is exposed to indirect UV radiation that has been reflected off the individual's skin, the material irreversibly changes color. The color change is compared to a graduated scale to determine if the level of exposure is harmful. The device is designed for single day use and is disposable. One of the issues with this type of device is that attaching the device on the skin may leave a shaped area that has not been as exposed to the sun as the surrounding region. This leaves a less tanned shaped region on the body which some individuals find aesthetically displeasing. Furthermore, the device is intended as a single use device and consequently is of no assistance for monitoring cumulative exposure to UVR over a period of time.
Yet another device is disclosed in U.S. Pat. No. 6,132,681 issued to Faran et al. The device is contemplated to be in the form of a sticker or badge that is attachable to the individual or to their clothing, for example. The device is manufactured to indicate when a specific quantity of exposure has occurred, namely 1 MED. The patent defines a MED as “the radiant exposure of the UV radiation that produces a just noticeable erythema (i.e., sunburn) on previously unexposed skin.” (Clarification added by the applicant). The device includes photochromic compounds which irreversibly change their color after exposure to this 1 MED dose of UVR and once this irreversible change has occurred, the individual is supposed to get out of the sun and throw away the device. The device takes into account the fact that individuals have differently pigmented skin and a 1 MED dose of UVR for a fair skinned individual differs greatly from a 1 MED does for a darker skinned individual. Consequently a number of differently graduated devices would be made available and the individual will purchase the device most appropriate for their skin color. The device does not include a graduated scale that indicates a range of possible exposures to UV radiation—just a single color change when the full dose of radiation has been received. This device again may leave a less tanned region on the person's body and is only meant for single use and is therefore of little assistance in monitoring UVR exposure over several days.
Finally, Hovorka discloses in U.S. Pat. No. 6,060,321 a disposable UV dosimeter that has a test zone that changes color when exposed to UVR over a period of time. The test zone is surrounded by a color panel which includes at least three areas that indicate whether the individual has been exposed to a low, moderate or high dose of UVR. The user compares the test zone with the color panel to determine the level of UVR to which they have been exposed.
These and numerous other devices have been developed for determining the level of an individual's exposure to UVR. However, these devices have been designed for single day use. Most vacationers tend to go to sunny destinations for an average a length of about a week. The daily exposure to the human skin is cumulative over this length of time. Each day can have varying amounts of sun intensity and the user may or may not be exposing themselves to the sun each day or part of the day.
A number of other UV monitoring devices which include complex electronic circuits, display panels and the like, have been proposed for monitoring exposure to UVR over a period of time. These devices are not contemplated to be disposable, would typically be relatively expensive and may be prone to failure because of all their component parts.
Accurate monitoring of the sun's intensity on humans is problematic as humans are three-dimensional in nature. They therefore tend to have different parts of their body exposed to the sun at different times and at different rates. The angle of the sun to the monitoring device has a large effect on how much exposure the card will record. There are also two different types of possible users of UVR monitoring devices. A responsible adult will use the device to monitor their personal exposure and will likely place the device correctly for exposure to the sun. When they are in the sun, they will monitor the device throughout the period and decide if the exposure is excessive. The other type of user would be a person who is taken care of a group of children in a common area such as a park or swimming pool. Each of these applications requires a different device for monitoring UVR exposure.
It would be therefore be desirable to have a UV monitoring device that would last the duration of a typical vacation, i.e., one week, and which would provide both daily and weekly readings of UVR exposure. The daily reading is important so that the individual can ensure they are not being exposed to too much UVR from the sun in one single day. The weekly cumulative readings are important so as to monitor the total sun exposure received during a week's vacation.